Find the value of $13+4.7\times10$13+4.7×10

Find the value of $2.6+0.84\times10$2.6+0.84×10

Find the value of $8.4-0.44\times10$8.4−0.44×10, giving your answer as a decimal.

Find the value of $0.023-0.020+0.003$0.023−0.020+0.003, giving your answer as a decimal.